The ChIP DNA was purified with AMPure beads (Beckman). ChIP and input DNA libraries were prepared using the NEBNext ChIP-seq Library Prep Master Mix Set for Illumina (NEB) following manufacturer's protocols. The quantity was determined using the Qubit High Sensitivity DNA kit (Life Technologies) and library size was determined using the Bioanalyser High Sensitivity DNA kit (Agilent). Libraries were quantified using the Universal Library Quantification Kit for Illumina (Kapa Biosystems) and run on AB StepOne Plus Real-Time PCR (Applied Biosystems). Libraries were diluted to 2nM and sequenced at the MRC Imperial facility using the Illumina HiSeq 2500 platform to obtain single-end 50bp reads.